The Hazards of Too Much Sitting

Submitted by Jennifer Salter on Tue, 05/26/2015 - 01:45

We all know that we are supposed to exercise to protect ourselves from numerous health problems. There is unequivocal evidence that regular moderate- to vigorous-intensity cardiovascular activity plays a significant role in preventing cardiovascular disease (CVD), type 2 diabetes, obesity and some cancers (ACSM, 2006). However, few people realize that daily exercise cannot entirely mitigate the deleterious effects of too much sitting. That is to say that even if you get the recommended 30 minutes of recommended daily physical activity, sitting for the majority of your other waking hours is actually very harmful. The emerging science of inactivity physiology studies the biological ramifications of sitting for extended periods of time.

The majority of North Americans sit for most of the day. Between long commutes to and from work, being in front of the computer most of the day, and watching television or using the computer to surf the net at night, most people’s time spent up and about is minimal. In fact, it is estimated that even those who are physically active spend about 90 percent of their day in sitting behaviours. Among the 7278 men and 9735 women enrolled in the Canadian Physical Activity Longitudinal Study, there was a strong association between sitting and mortality risk from CVD and all other causes, after adjusting the data for potential confounding variables (eg, age, sex, smoking status, alcohol consumption, leisure time, and physical activity). The highest mortality subpopulation group is obese men and women who spend most of their waking time sitting. Why is this? Research has pointed to several possibilities: • In animal studies with rats, it has been found that when they are not allowed to stand there is a dramatic drop in lipoprotein lipase, the enzyme in the leg muscles that captures fat out of the blood to be used by the body as fuel. Thus, with consistent sitting, blood triglyceride levels start to soar which increases the risk of CVD. It has been hypothesized that this same process occurs in humans. • A clinically relevant decrease in HDL (“good”) cholesterol is observed with regular, prolonged periods of sitting. What Can Be Done? • Stand up and walk around your office every 30 minutes. • Set a timer on your computer or smart phone to remind you to get up regularly. • Stand up and get some water. • Walk to your colleagues offices instead of emailing them. • Walk to the farthest bathroom in your workplace (if more than one is available). • Always stand and walk around the room when on the phone. • Take a 5-minutes walk break with every coffee break. • At night when watching tv, take breaks during commercials to do standing stretches or some easy leg exercises. • Stand up while watching tv to do single leg balances. • Capitalize on Non-Exercise Activity Thermogenesis (NEAT) – in a nutshell, it has been found that people who tend to fidget and move around spontaneously throughout the day have lower levels of obesity, because they burn more calories than their sedentary counterparts. The bottom line is get your exercise in, but stay as active as you can during your other waking hours! References